As is well known to those skilled in the art, hydrocarbons may be converted to hydrocarbon derivatives containing functional groups (typified by halogen groups); and these may serve as a starting point for the preparation of further derivatives.
Terminally substituted alkanes (especially those with 8-18 carbons) derived from n-paraffins are valuable chemical intermediates in the production of fatty acids, amines, alcohols, esters, and sulfonates for use as detergents, fabric softeners, lubricant additives, plasticizers, etc. (F. Asinger, Paraffins: Chemistry and Technology, transl. B. J. Hazzard, Pergamon Press, Oxford, 1968, pp. 735-6). By contrast, secondary substituted paraffins derived from these same paraffins generally decompose to form olefins or are unreactive when attempts are made to transform them into alcohols, sulfonates, etc. (Asinger, p. 736; H. Krauch and W. Kunz, Organic Name Reactions, John Wiley, New York, 1964, p. 444; Jack Hine, Physical Organic Chemistry, McGraw-Hill, New York, 1962, Chapt. 6).
The treatment of n-paraffins, under a variety of reaction conditions to introduce e.g. chlorine, always gives rise to a mixture of 1-chloroalkanes and secondary chloroalkanes. Although there are physical methods (U.S. Pat. No. 3,426,086) for separating the two classes of compounds from one another and chemical means of separation are feasible utilizing the different orders of reactivity for these compounds (for examples, see Chem. Abstr. 62 11671 (1965); D. J. Hurley et al., I & E.C. Prod. Res. & Devel. 4 44 (1965), no attempts have been made to isolate the 1-chloroalkanes from such chlorination mixtures for use as chemical intermediates because the 1-chloro isomer is formed in very low selectivities. For example, chlorination of n-dodecane using a variety of chlorinating agents and reaction conditions gives only 11-13% selectivity of the monochloro product to 1-chlorododecane (G. A. Russell article in Free Radicals Vol. 1, J. K. Kochi, ed., John Wiley, N.Y., 1973).
Several attempts have been made to influence the position of chlorine atoms in an alkane chain by use of solid absorbents. Deno and co-workers (N. C. Deno, R. Fishbein, and C. Pierson, J. Am. Chem. Soc., 1451 (1970)) were able to increase the .omega.-selectivity for chlorination of a fatty acid by first chemisorbing the acid in .about.3 wt. % concentration on neutral alumina. They reasoned that the acid molecules were rigidly aligned in parallel to one another causing only the .omega.-positions to be open to attack from Cl.sub.2 gas molecules. Eli Perry (Eli Perry, J. Org. Chem. 35, 2053 (1970)) was able to modify the course of reaction between hexane and chlorine by pre-adsorbing the paraffin on a Linde 13X sieve. This caused an increased selectivity to 1-chloro-hexane (an increase in the relative reactivity of primary to secondary hydrogens in hexane towards Cl.sub.2). This effect was presumed to be due to the molecular sieving properties of the zeolite and was sensitive to the pore size of the sieve.
It is an object of this invention to provide a novel process for selective conversion of hydrocarbons. Other objects will be apparent to those skilled in the art.